The pulley is pressed on. Try using a puller bolted to the fan attaching holes with the jackscrew bearing against the center shaft. GMC pump rebuild kits are available on Ebay.
Jerry


"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!